1. Field of the Invention
The present invention relates to a method, system, and program for generating a blank page in a print job and, in particular generating a blank page for a last page of a duplex print job.
2. Description of the Related Art
In printing systems, a rasterizer (RIPPER) is a component that converts print data, such as vector graphics or page description language commands, into a bitmap that instructs the printer where to deposit ink. For instance, All PostScript printers contain a RIPPER that converts the PostScript commands into bit-mapped pages that the printer can output. The printer deposits ink at the pixel locations on a page having a corresponding xe2x80x9conxe2x80x9d bitmap value, and remains inactive at pixel locations having a corresponding xe2x80x9coffxe2x80x9d bitmap value.
A duplex print job is a print job that prints on both sides of the paper. Thus, with duplex print jobs, the RIPPER will generate separate bitmaps for the front and back side of each page. Oftentimes in a duplex print job, the back-side of the last page of the print job may be blank. The print system must include a methodology to handle a blank side of the last page. In certain prior art systems, to handle a blank side on the last page of a duplex job, the RIPPER generate a bitmap including all xe2x80x9coffxe2x80x9d values or zeros to cause the printer to print nothing on the blank side of the page. To implement this blank page approach, the RIPPER could either generate a blank bitmap or maintain blank bitmaps in memory for each possible paper size. In either case, this technique is disadvantageous because RIPPER processing cycles and memory are needed to generate the blank bitmap or maintain blank bitmaps for different paper sizes in memory for the blank back side of the last page.
Other prior art systems handle a blank side of the last page of a duplex print job by providing no data for the blank back side. This causes the printer engine to generate error interrupts on each scan line being processed as the scan line is passing through the printer. The printer driver, also referred to as the printer mechanism or printer controller, must then handle these error interrupts from the printer engine and determine to ignore the errors received when the blank side is being processed. This technique is disadvantageous because the generation of error interrupts by the printer engine for each scan line slows down the printer engine process to generate the error interrupts and slows down the printer mechanism process by requiring the printer mechanism to handle and choose to ignore each error interrupt.
Thus, there is a need in the art for an improved technique for handling a blank back side of the last page of a print job that avoids some of the above described disadvantages with current art tec
To overcome the limitations in the prior art described above, preferred embodiments disclose a method, system, and program for generating a blank side of a page in a print job. Bitmap data is received for at least one side of at least one page of a print job. The bitmap data for the at least one side is sent to a printer engine to control the printer to print the print job over a data path. For a blank side in one page in the print job, a command is issued to resend bitmap data for one side previously sent to the printer engine. A further command is issued to disable the data path to cause the transmission of white data to the printer engine. This disabling of the data path prevents the resent bitmap data from reaching the printer engine, which, in turn, causes the printer to produce the blank side in response to receiving the white data.
In further embodiments, the data path includes a pin connector that is used to communicate data to the printer engine. In such case, the disable command disables the pin through which bitmap data is sent to the printer engine.
In still further embodiments, the blank side may be the last page of the print job or the resent bitmap data may comprise the last sent bitmap data.
Still further, the print job may comprise a duplex print job. In such case, the blank side may comprise a back side of the last page of the duplex print job and the bitmap data resent may comprise the bitmap data previously sent for a front side of the last page of the print job.
Preferred embodiments provide an improved technique for generating a blank side of a page, such as a blank back side for the last page of a duplex print job. Preferred embodiments do not require generating or maintaining a bitmap for a blank page, i.e., a bitmap of all zeros, as do certain prior art techniques, thereby conserving processor cycles and memory over such prior art techniques. The preferred embodiments further avoid generating numerous error interrupts which result in prior art techniques that send no data to the printer engine for the blank side. Instead, the preferred embodiments send data thereby avoiding the need to generate and handle interrupts.